Prevention of condensation

The outer two air streams are quite different in terms of temperature andabsolute humidity (streams A and C).This leads to condensation (misting) where the streams meet,as appears from the black dotted line in the Mollier diagram.To prevent condensation,a middle stream is added (stream B).This stream is also taken in from the cold store,and heated to reach a higher temperature.The relative humidity of the middle stream is low,so it can take in moisture from the hot ‘front hall area stream’ (A).The dry ‘cold store stream’ and the humid ‘front hall stream’ do not intermix,nor does any mis- ting arise (see red line in Mollier diagram).The discharge temperature of the middle stream (B) can be automatically controlled.At higher temperatures in the ambient area (see fig.1),a higher discharge temperature is needed to prevent misting,contrary to fig.2,where the front hall has a lower temperature.The temperature in the front hall is read and the discharge temperature of the middle stream (B) is exactly controlled using several sensors,so misting is prevented.This allows you to keep the air curtain manufacturer’s electrical capacity as low as possible in all circumstances (thus saving on energy),and yet warrant a mist-free passage.

Mollier-diagram

Fig.1 At higher temperatures in thefront hall (in the summer),stream B has a higher discharge temperature to prevent misting.

Fig.2 At lower temperatures in the fronthall (in the winter),the discharge temperature of stream B adjusts automatically to such lower temperature as is exactly needed to prevent misting.

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